Cuckoo hashing holds great potential as a high-performance hashing scheme for
real
applications. Up to this point, the greatest drawback of cuckoo hashing appears
to be that there is a polynomially small but practically significant probability
that a failure will occur during the insertion of an item, requiring an expensive
rehashing of all items in the table. In this paper, we show that this failure
probability can be dramatically reduced by the addition of a very small
constant-sized stash. We demonstrate both analytically and through simulations
that stashes of size equivalent to only three or four items yield tremendous
improvements, enhancing cuckoo hashing’s practical viability in both hardware and
software. Our analysis naturally extends previous analyses of multiple cuckoo
hashing variants, and the approach may prove useful in further related
schemes.